Subject: Re: Splitting sa1111 support codes.
To: Ignatios Souvatzis <email@example.com>
From: David Laight <firstname.lastname@example.org>
Date: 04/26/2003 10:38:53
> In generally, this sounds right. However, I notice that you don't correct
> the mistake of the old NetBSD code that assumes that
> SA110y mostly== SA111y
> This is not the case, and I suggest that you move away from shared files
> unless your reading of the documentation shows you that there really are
> shared structures. At least in new files.
IIRC  the only significant difference between the SA1100 and SA1110
is the DRAM controller (the former supports EDO and the latter SDRAM).
The SA1101 and SA1111 are, however, entirely different beasts and
are not really anything like each other.
As well as functional differences, there is the major difference
in that the SA1111 sees all the address bits so its registers are
on byte/word boundaries, OTOH the SA1101 only sees the (equivalent of)
DRAM RAS address bits so its registers are on 4k boundaries .
Mapping the SA1101 needs to be done with large (1MB) pages - especially
if you want the VGA pallete - or you run out of DRAM for page tables.
 I've written drivers for all the hardware on a SA1100/SA1101 system
and looked at doing teh same for a replacement SA1110/SA1111 system
that didn't get off the drawing board.
(yes, I even got the VGA output of the SA1101 working in both modes...)
 this depends on the DRAM organistion in the system.
David Laight: email@example.com